Failure mechanism of roadway surrounding rock in integration mine and its support optimization

Aiming at the surrounding rock control problems such as continuous deformation of roadway and failure of original support cause by the width decrease of coal pillar when expose the gob during roadway driving in integration mine，the roof structure and the distribution of stress field of the gob side entry with different width coal pillar were analyzed，and the variation of the position of the peak abutment pressure with the width of coal pillar were understood.The main reason for the failure of the original supporting of roadway is that the stress environment of surrounding rock is poor and the supporting strength is low.Furthermore，the stress distribution of surrounding rock in different roadway sections was analyzed through numerical simulation，and the U type steel telescopic arch support was proposed to optimize the section of the original rectangular tunnel.The roadway space was constructed combined with cement backboard and filling cushion material.The monitoring results show that in recent two years the surface displacement value is 0，and the roadway shotcrete stay intact.The monitoring results shows that it is reasonable and feasible to use the U type steel telescopic arch support for the optimization of roadway support during exposed gob section，which provides technical reference for tunnel support under similar geological conditions.